Due to the improved fit and fluid sealing properties provided by leg elasticization, manufacturers of disposable diapers have, in recent years, developed various methods and apparatus for attaching elastic strips to the leg areas of the diapers. Because of the high speed, continuous nature of diaper manufacturing methods, virtually all of the commercially practicable processes have utilized a continuous elastic ribbon affixed to the diaper in the leg areas and subsequently cut either prior to or as a part of the severing of the continuous web into separate diapers. Typical of these processes and apparatus is that disclosed in U.S. Pat. No. 4,081,301 to Buell. This patent discloses adhering of the continuous elastic ribbon only in discrete, intermittent areas corresponding to the leg areas in a finished diaper. The ribbin and the diaper are then simultaneously cut at the waist of the diaper when the continuous web is cut into separate diapers. The drawback of this process is that it is inefficient from the material use aspect in that it leaves an unneeded length of elastic attached to the diaper. Another approach to handling the problem is disclosed in U.S. Pat. No. 4,227,952 to Sabee. In the method of this patent, the elastic ribbon is continuously applied to the web, however, before the attachment of the ribbon to the web, the latter is folded in the areas of the web corresponding to the waist areas of the finished diapers. Consequently, the elastic ribbon is attached to the web only in the leg areas of the finished diaper. The elastic ribbon is then severed at the points opposite the folded areas of the web and the web is then unfolded so that elastic is only in the leg areas and the waist areas contain no unneeded elastic. The problem with this method and the apparatus used in it is that they are quite complex and difficult to operate at the high speeds required for commercial usefulness.
It is a principal object of this invention to provide a method and apparatus for attaching a continuously moving elastic ribbon to a continuously moving web only in the areas of the web corresponding to the leg areas in finished diapers and removing the portions of the elastic ribbon between the attached areas in a simple and commercially practicable manner.